- the build is now much more strongly oriented on cmake.
The wmake wrapper only adds some minor versioning on the build
and uses a standard CMAKE_INSTALL_PREFIX to define its installation
location.
These changes can make it easier for some packagers (eg, spack)
to manage.

- if sigFpe is enabled within OpenFOAM, any errors in the Catalyst
pipeline will potentially kill the entire simulation.
- use the new sigFpe::ignore helper class to manage a local disabling
of SIGFPE handling.

- previously had separate function objects for each category of source
(finite volume, finite area, lagrangian). This lead to isolation of
the individual input sources, which highly restricted the flexibility.
- now have a single catalyst function object with an arbitrary number
of inputs (sources). The catalyst channel name is that of the
corresponds dictionary name. For volume mesh sources, it is possible
to address "mesh" and "patches" sub-channels.
Eg,
mesh = coprocessor.CreateProducer(datadescription, 'myregion/mesh')
This restructuring also aims at integration of other OpenFOAM content
(eg, surfMesh, sampled probes, sampled surfaces) as a future
development.
- the output directory (by default "<case>/insitu") is passed onto
catalyst as its working directory, using the upstream patches that
now close issue #4